I'd like to add a route on a solaris 10 for the multicast subnet (224.0.0.0) using virtual NIC device, but was not able to do so. "route add" command can add a routing entry using physical NIC. Any help or advices on how to do that on a virtual NIC are appreciated.

some backgroup information:

Here is a solaris 10 that has such route entry configured already, but don't konw how it was done:
$ netstat -rn